1. Field of the Invention
This invention relates to polyhydroxyamido-containing organopolysiloxanes and to a process for preparing them.
2. Description of the Related Art
U.S. Pat. No. 6,958,410 B2 describes amido-functional aminopolydiorganosiloxanes that have hydroxy carboxylic acids attached via the amido function. These linear siloxanes contain essentially lateral polyhydroxyamidoalkyl groups. They are used as softeners for textile finishing.
EP 1081272 describes polyol-functional linear siloxanes that additionally contain amino and/or amido groups, wherein the polyol groups are exclusively attached as lateral groups. These compounds are used as a textile finish to reduce the tendency to yellow in the course of processing compared with conventional softeners.
Polyhydroxysiloxanes are known from U.S. Pat. No. 4,591,652. They are synthesized by reacting silanes that bear amine-terminated substituents with aldonic acid lactone.
JP 62068820 A in turn describes in general terms the synthesis of organopolysiloxanes having saccharide residues from aminosiloxanes and saccharide lactones. They are used as primers on mineral and metallic surfaces.
EP 879 840 A is directed to linear organopolysiloxanes that contain polyhydroxy groups and polyether groups in the same molecule. These groups can each be attached to the siloxane chain in its lateral positions or else the terminal positions.
WO 2006/071772 discloses crosslinkable saccharide-siloxane compositions and also crosslinked formulations and coatings prepared therefrom. The α,ω-aminosiloxanes used as starting materials in the examples are 100% endblocked with amino groups. The polyhydroxy-functional saccharide-siloxanes obtained therewith are solid or have a wax-like or rubbery consistency.